The Clinical Resource core will serve as the central facility for all clinically related activities of the Program Project Grant and is functionally divided into two sections: 1) Clinical Screening and Evaluation Section: This section will be responsible for the clinical evaluation of all members in the MEN-2A and MEN-2B and FMTC kindreds. The evaluation will include a medical history, physical examination and the tests necessary to establish the diagnosis of a specific endocrine disease state. This section will also evaluate patients who present with sporadic endocrine tumors represented in the MEN-2 and related syndromes. The procurement of all medical records on patients affected with the endocrine diseases under study will be the responsibility of this section; this includes hospital records, operative notes, pathology reports, pathology slides, paraffin blocks of fixed tissues, and diagnostic x-rays. During the screening process, biological samples will be obtained on patients and it will be the responsibility of this section to transfer them to the Laboratory Resource Core. 2) Data Analysis Section This section will serve to maintain and to analyze all data relative to clinical screening and evaluation and to linkage analysis. Specific areas of study will be determinations of penetrance, heterogeneity and segregation analysis. Also calculations of recurrence rates, disease free interval after surgery and survival rates will be determined. In addition, the linkage analysis in Research Projects 1 and 2 will be assisted by this section.